According to BBC Sport, severe myopia means that all Im sees of the target, 70 meters away, is a blurry yellow blob. He chooses not to wear glasses, he says, because he has grown used to seeing the target that way.

He has nonetheless won two team golds at previous Olympics and is currently ranked number two in the world.

Im and his team mates, Kim Bub Min and Oh Jin Hyek, also set a new team world record at London's Lord's cricket ground today. Taking first, second and third place respectively, they racked up 2,087 for 216 arrows and beat the previous top score by 18 points.

South Korea's head coach, Jang Young Sool, told Reuters such success in the ranking round would give the team confidence heading into the next stage of the competition – though Im said he wouldn't let it go to his head.

"It's just the first round so I won't get too excited about it," he said.

The only archer ranked higher than Im, world number one Brady Ellison of the US, placed 10th today with 676. Larry Godfrey of Great Britain came third with 680, followed by Japan's Takaharu Furukawa with 679.